Preheat the oven to 400°F (200°C). In a large bowl, toss the sweet potatoes, carrots, and zucchini with the oil, paprika, cumin, and a pinch of salt. Spread the vegetables in an even layer on a baking sheet and roast for 25-30 minutes, or until tender and lightly browned.

Meanwhile, add the lentils, water, and a pinch of salt to a saucepan over medium heat. Bring to a simmer, cover, and cook for 20-30 minutes, or according to package instructions, until the lentils are soft. Drain off any excess water and set aside.

To make the dressing, whisk together the hummus, Dijon mustard, lemon juice, and a pinch of salt. Add a small drizzle of water and stir until the dressing reaches a pourable consistency.

Combine the cooked lentils, roasted vegetables, and dressing in a bowl. Toss gently to coat and serve.